Stoker



5 1944- G. A. FERRELL 2,339,776

STOKER Filed 001:. 28, .1940

Afro/W05 Patented Jan. 25, 1944 ST'OKER George A. Ferrell, Reading, Pa., assignor to Ferrel Stoker Company, Reading, Pa., a corporation of Pennsylvania Application October 28, 1940, Serial No. 363,069

4 Claims. (Cl. 110-101) My invention relates to stoker devices, and has reference, more particularly to a furnace stoker including novel feeding and ash removal means severally and in combination.

Heretofore, many furnace stokers have been suggested and employed, including those which merely feed, and those which feed fuel to and. discharge ash from the fire beds.

Such prior stokers have had many disadvantages, such as excess cost, undue complication and number of parts, breaking of shear pins and other parts from clogging of fuel and the presence of foreign bodies, such as nuts and bolts in the fuel which cause fly ash; other devices include fuel feed and-ash removal means as separate apparatus, such apparatus usually necessitating the use of expensive fuel, while adapted only to furnaces of limited variety, and further being difiicult to install, inefficient in burning the fuel, and confined to furnaces of particular style.

A furnace stoker which merely automaticallyfeeds, irrespective of its many advantages, such as smaller cost, and availability to a larger class of usage in certain instances, still leaves substantially as great a problem as it solves, and as much trouble as it avoids, in the necessity for the manual discharge or removal of the ash. from the grate or fire bed.

Certain of the former stokers do not burn all of the fuel, but leave unburned portions of it in the ash. Others operate against gravity in feeding the fuel and removing the ash, have parts maintained in position as in burners or stokers of the older less efiicient types, are easily deranged, stopped or injured so as to disrupt service causing inconvenience and expense, and readily clog and pack the fuel.

Among the objects of my invention are to overcome all of the above noted disadvantages of former stokers, both as to feeding the fuel and to removing the ash from the fire bed.

Another object of the invention is to feed fuel to a fire bed from the top, and remove the ash at a rate substantially in accordance with the consumption of the fuel at any selected temperature or heat.

Another object of the invention is to take novel advantage of gravity infeeding a furnace charge, maintaining the charge while burning, and re: moving the ash from said charge.

Another object of the invention is to move a burning fuel charge bodily in such relation to its feed-and consumption as to maintain the charge substantially constant.

Another object of the lnventionis to more thoroughly and effectively consume a furnace fuel charge.

Another object of the invention is to provide 1 a stoker, and a device for removing ash from the charge, severally and in combination, which' is simpler and less costly in construction, assembly and installation, than heretofore while being:

more economical and effective in operation, as

well as adapted to the use of less expensive fuel.- Another object of the invention is to produce a combined fire stoker and ash remover which is less expensive than former structures having.

both of said features, and that is more comparable in cost to devices heretofore comprising only thestoking feature. I

Another object of the invention is to provide a furnace stoker which is more rugged and dur-' able, that will not pack the fuel or require shear pins to guard against damage from such packing, or from the presence of foreign bodies, will j maintain a solid-particle fuel in an effective fluent state, and withal requires the minimum of attention.

ample hereinafter disclosed, furnaces fo heating dwellings.

With the stated objects in view, as well as advantages which may be incident to a utiliz a-; tion of the improvements, this invention com-, prises the elements and combinations thereof hereinafter described, illustrated in the drawings, and more, particularly defined by the C011,".

cluding claims; it being understood, however, that the several necessary elements constituting the same may be varied in proportion, arrangement, and operation, without departing from the nature and scope of said invention.

In the drawings:

Figure 1 is an outline or general view, partly; in front elevation and partly in section, of a, heater furnace, a main fuel supply bin, and a stoker constructed and arranged according to this invention, together with a convenient elec-' tric control means.

Fig. 2 is an enlarged detail view, partly in side: elevation and partly in section, taken substantially along the line 2..2 of Fig. 6, of an adjust:

able pawl-and-ratchet drive connecting mechanism.

Fig. 3 is an elevation, and partly in section along the line 3-3 of Fig. '7, of an adjustable drive connector for a fuel displacing element of the invention.

Fig. 4 is a view of a portion of the device illustrating the relation between a fuel feeder and a movable hopper element in one phase of operation of the device.

Fig. 5 is a view similar to the preceding but showing the parts. in-a different: position.

Fig. 6 is a top plan view, on an enlarged scale, with parts broken away, of the stoker structure; said view being taken at about the lower central portion of Fig. 1; and,

Fig. 7 is a view to the same scale, taken at right angles to Fig. 6, but showing the structurethereof partly in side elevation and partlyinsection, some parts being broken away and other parts of Fig. 1 being included;

Referring to Fig. 1, the apparatus, therein shown comprises, in general, a. domestic-heating furnace F, a main. fuel supply bin B, a door-Dgof anash pit B, aibalanceweight W- for thedoor;

D, a stoker including a box-like structure S. and a. hopper I-I constituting the mainpartsof this invention, as well ascircuit control elements-later on set forth.

The set up-illustrated in this. example, so. far as. the furnace F isuconcerned, is a. conversion installation, with said furnace being :oneof known or. standard. type having an aperture cut .inzits right. hand'side, as-viewed in Fig. 1,, for reception of the boxstructure S.

Also, the balance weight W is an expedient known, while the pit P is similar to. other pits, andan incident of oneformofthe invention only in its novel shape, locationand relation, to other parts, but. which v maybe varied and replaced by other means.

The binB is. also, ingeneral, similar to. known fuel supply chambers, being novel only in its.

Particular relationto other featuresof the inventiom. such as having7 its floor a: continuation. of, or cooperating with, the floor'ofthehopper H.

Referring to Figs. 6 and '7, in which the; main features. of. the invention arebettershown, the stoker. S,.is of box-like. formation, as. above mentioned, constructed, of, castorsheetmetal. such as iron, having an. openend, l.5-..for insertion. into the furnace F, as. through the above-mentioned rightv side. opening, as. far as. an. upper vertical. edge IS on each of the side walls I! and. i8, each.

said wall including a forward portion havinga top edge sloping to the open. end=.of.- the. box,.. and

joined tothe. other by a bottom 21,, and'the box.

beingclosed. at. its rear end outside-thefurnace F by a wall 22.

Vertical slots 25- are, provided. in the. side walls l1. and; i8, and acover 2G. closes the top, of that.

portion; of. the box structure, SoutsidethefurnaceF.

A metal fuel bed-plate or. grate. 21,. forming, substantially a; partition intermediate. the, top. and bottom of the box structure S, alsoconstitutes the top f, anair chamber. 30. completedby theside walls IR. [8,. b'ottom-v 2]. and. outside: wall, 22. of box-structure, S.

Thegratefl is. secured to.the outsideand side, walls; 22;, l1, l8 of the box. structure. S. in. which, it slopes downwardly from the, rear wall," to, a position beyondthe. front. edge, of'thehottom 2 I over, thepit. P, at. which pointitLis reinforced, asby -an angle plate3 I... Per-forations 32. through the, grate, 21' are of such, diameter, number and distribution relative to the particular fuel. intended,.in. this instance barley, coal,,as to provide proper support for said fuel, without having it pass through said grate into the air chamber 30, and to ensure a, proper flow of combustion air from said chamber.

The angle or slope of the grate 21 is also such, in consideration of the fuel employed, as to maintain the latter in such stable equilibrium, or repose, when not disturbed beyond a certain point, thuspermitting the fuel charge to be gradually orintermittently urged bodily downward on the grate 21 at a rate substantially in proportion to the formation of ash at a selected heat.

Thus, there is never any excess fuel on the grate 21 for the required heat, and the operations of adding the fuel and discharging the ash are substantially such as to render the burning of flash character.

A plate-like member 35, which operates as a fuel pusher, is disposed on, and across, an imperforate portion of the bed 21, at a position on the slope thereof above the; perforations- 32, and. has lugs. 36 at. each upperrear corner thereof, from: which rods 31 and 38 project through slots- 40,, parallel to the. slope of the grate 2.11., inthe side walls I! and I8, respectively, atthe rear sideof the, fuel charge 4! on said grate.

-A fuel feeder, or delivery element is, inthisinstance, formed as a drum of substantially cam shape in cross-section, seeparticularly Figs. 4 and 5, having one so-called high. point 46. leading. gradually around the drum axis to a low point. 41 precipitately under the high point to form a. radial fuel-receiving shoulder between said, points. The drum 45,.is mounted on short and.

long, trunnions or shaft ends 5i and 5.2. that,

extend throughthe slots 25, and are. journaled in, bearings and, 56 on the side walls I] and, l8, respectively A gear wheel 60'. is, fixed. tothe. short trunnion. 5| outside the. box at the side wall I], and, a duplicate gear wheel BI is fixed. tothe longer trunnion 52 adjacent to the outer. end. thereof to provide spaceon the latter. for a.worm. drive-62., fixed'in positionrelative to the. trunnion-52, be.-

- tween the bearing'ifi' and the gear wheel 6],

Gear wheels 65, under the, gear wheels BIL-and 6i with which they mesh, arefixedto. tl'llnnions. 66 journaled in bearings 67, Fig. 3;..on,.the -side.- walls IT and I 8, respectively. Only oneot each of the gear Wheels 65, the trunnionsciili, and the bearings 61 is shown in the drawings, seepartieularly Figs. 3 and 7;.

A link or pitman 70 ispivotedlat one end, to

a headed pin H on each, gear wheel 65 eccentric to the, corresponding trunnion 6,6. and, at, the, other end, to the rod 31:01: 3.8., Thisarrangement is such as to provide reciprocation of, the fuel pusher 35 upwardly anddownwardly, on, the slope of the fire grate 21 while maintaining. its forward or active edge parallel to the feeder drum. 45....

As seen in Figs. 3. and. 7.. each. gear wheel. 65, has a radialouter-facegrccve rendered undercut. or, of dovetail. section, by. members, 1.5..fixcd. to said; wheel... A. Wedge lilreblock. 1.6., in.the .r-adial roove defined, by the members, 1.5,,hasa recess and, an. aperture for receiving the. head. of, the: pin H, and a plate washer ll, around thepin LI, spans. the groove against. the membcrs.1,5,.

By releasing. lock nuts 80,v binding. the, block; 1

. to the gear Wheel 65, said, block and the pin ll,

. in any position withinthese limitsbytightenin the nuts 80. Thus, the reciprocatory stroke of the pitfnan .10 and the fuel pusher 35 may be adjusted according to temperature and other conditions of any particular service or installation.

The hopper H illustrated, comprising a stationary body portion 8| of flat sided taper-section converging vertically and horizontally from an aperture in the bin 13, to a position just inside the stoker structure S. This hopper body portion BI is thereby entirely enclosed about its length from the bin B to the stoker structure S.

Inside the stoker structure S, the hopper body portion 8| communicates into a chute 84, open at the top, which is pivoted to the structure S by pins 85 engaged in lugs 86 on said structure, and in end bearing portions 81 at opposite sides of the chute 84.

The forward extremity of the chute 84 is supported by the feeder drum 45 so that, as the latter rotates, counterclockwise, as indicated by arrows in Figs. 4 and 5, the chute 84 is gradually raised to the high point 45, as indicated in Fig. 4, and suddenly dropped therefrom to the low point 41, as indicated in Fig. 5.

The cross-section of the feeder-drum 45 may, of course, be varied to alter the shape and dimensions of the shoulder 58, to provide more than one such shoulder, or shoulders of different shapes and spacings from each other, in order to varythe time of raising and lowering of the movable chute 84, and equivalent results obtained in other ways, each of which forms may have advantages over the others depending upon various conditions of installation, such as costs, capacity and other factors.

During rotation of the feeder drum 45, with the chute 84 supported thereby between: the points 46 and 41, the fuel is not delivered to said drum, but upon dropping from the high point 46, fuel at the mouth of the hopper stationary part 8| is jarred and deposited on the shoulder 5!] and on the adjoining cam surface of the feeder drum 45 for a predetermined extent from said shoulder. Upon continued rotation of the feeder drum 45, the shoulder 50 attains an angle at which the deposit is released to the charge M on the grate 21.

To provide even fiow of the fuel, and ensure against stoppage thereof in the hopper stationary part 8|, agitator means is provided, in this instance, in the form of a shaft 90 having staggered radial prongs or pins 9| thereon, and rotating counterclockwise, as indicated by the arrows in Figs. 4, 5 and 7.

The shaft 94 is journaled in the sides of the body part 8| and protrudes a suflicient distance, from one side, to support a sprocket wheel 92, shown only in Fig. 7, between which and a sprocket wheel 95 on the trunnion 52 extends a chain drive 98.

As seen in Figs. 6 and '7, a worm-screw 91, meshing with the worm wheel 62, is fixed to a shaft I00 that is journaled in lateral extensions IBI of the bearing block 56, and in a bearing I02 on the side wall I8.

Referring also to Fig. 2, a ratchet wheel I05, fixed to the shaft I04, cooperates with a pawl I06 pivoted to one arm I 41 of a rock lever IIB fixed to the shaft I00, and having a fork extension H2 between which is pivotally mounted a block II5, as by trunnions or stub shafts H6, only one of which is indicated, see dotted circle in Fig. 2.

Slidably engaged through the bore of the block I I5, is a rod II! which extends to a follower I 20 about a circular cam disk I2I, said disk being eccentrically fixed to a shaft I22, journaled in a bearing I25 on'the rear wall 22 of the stoker structure S, and having secured thereon a Worm wheel I26 in mesh with an endless screw I21 on the drive shaft of a suitable motor I30.

Two sets of lock nuts I3! and I32 are carried by the rod H1 at opposite sides, respectively, of the block II5, for adjusting the rotary steps of the ratchet wheel I05 relative to the constant throw of the slide rod II'I effected by the cam disk I2I. By adjusting the nuts I32, the throw of the rock lever Ill], and consequently that of the pawl I05, may be varied to turn the ratchet wheel I05 to the extent of one, or more, teeth for each reciprocation of the rod II'I, whereby the rate of operation of the pusher 35, the fuelfeeder drum 45 and the agitator 94 are variable.

The main motor I30 is mounted on a bearing bracket I35, and under it is disposed a motor-.-

operated blower 36 for imp-elling air, through an opening in the rear Wall 22 of the stoker structure S, into the air chamber 36 beneath the fire grate 27, as indicated by the dotted-line ar-' rows in Fig. 7, for projection through the perforations 32 in said grate.

As' typically indicated in Fig. l, the main motor I30, as well as the motor for the blower I36, are connected by circuit conductors l4!) and MI in parallel to conventional service lines I42, through an adjustable thermostat I45, conveniently in series with the conductor MI. I

By adjusting the thermostat I45, the stoker S of this invention may be caused to operate, as above set forth, to maintain any desired temperature in a building irrespective of the outside temperature.

For a given inside temperature, the stoker S will operate more or less frequently, according to whether the outside temperature is low or high, respectively, relative to the selected inside temperature.

If,asoccursbetweenseasons and at other times, the temperature differential between the interior and exterior of thebuilding maintains the thermostat I45 so that successive feedings by the drum 45 cease, or are so far apart that the combustion of the charge 4| may become extinguished, or too low, and it is desired to maintain the fire, a suitable time control I46 may be provided. This control I46, indicated as of the electric-clock variety energized from the service lines I42, is adjustable so that, irrespective of the thermostat I45, said control may cause actuation of the stoker S at any desired intervals by actuating a switch I41, which closes and opens the circuit represented by the conductors I40 and MI, also controlled by the thermostat I45.

Thus, the feeding of fuel may be gauged'so as to merely maintain the fire, until such time as the outside temperature may drop sufficiently to cause automatic resumption of control by the thermostat I45, or until all operation is discontinued.

The ash formed and pushed from the lower end of the grate 2'! is, in this instance, of substantially solid or clinker form, which breaks off in sections for deposit in a receptacle I31 in the pit P, or for disposition in other manner, and thereby does not pass through the perforations 32 in the fire grate 21.

It is contemplated that either, or both,the bin B and the ash pit P, or other fuel storage supply and ash disposal means, may be directly accessible from outside the building being heated; that irrespective of location, either may be of suflicient capacity to preclude frequent attention; and that other means may beprovided for supplying the fuel. and removing the ash from the building, so that, depending upon the conditions, structure, arrangement or other circumstance, the stoker S may be of maximum convenience and .minimum trouble for any given installation or service.

By its open, rugged, simple construction, the Stoker S may be provided in a wide range of sizes or capacities, all; the way from a size suitable to the so-called bucket-a-day hot water stoves for small or ordinary dwellings, to a size suitable for furnaces F of relatively large buildings.

The stoker S may be provided in any size, and arranged in batteries of two or more, in side-byside or other relation, such. as extending into a furnace F from different sides, or at various angles.

By its effective use of barley coal, the stoker S isof such economical operation as to absorb its cost. in a relatively short period of time, and is a marked improvement generally, in its field, in the other features set forth.

I claim as my invention:

1. A stoker comprising a grate, a horizontally pivoted chute sloping slightly downward from adjacent the pivot mounting to its delivery end over the grate, aligned means for receiving fuel from the chute for delivery thereby to the grate and cooperatively rocking the chute about its pivot axis, and said means including a shelf-like portion for receiving fuel on downward movement of the'chuteand being movable between a position for supporting said fuel and a position for discharging said fuel onto the grate.

2; A stoker comprising a grate, a horizontally pivoted chute sloping slightly downward from adjacent its pivot-mounting to the delivery end over the grate, and a rotatable drum across and above the grate having a cam-like cross-sectional shape for imparting rocking motion. to the chute, said drum having a shelf-like portion for receiving a deposit of fuel on downward rocking of the chute and for delivering said fuel from the shelf to the grate.

3. A stoker comprising a grate, means for feeding fuel to the grate including a drum across and over the grate, said drum being of cam-like section having a high point leading gradually around the drum to a low point precipitately under said high point to provide a shoulder between said points, a chute pivotally mounted parallel to the grate and sloping downwardly from the pivot toward the drum with its delivery end supported by said drum, and means for turning the drum about its axis whereby the delivery end of the chute is gradually raised to, and suddenly dropped from, the drum high point for flow of fuel onto said shoulder for delivery by the latter to the grate.

4. A stoker comprising a box-like structure having an open end for association with the ash receptacle of a furnace and including a bottom air chamber portion, a perforate grate between the side walls of the box structure and sloping downwardly from adjacent a closed end wall of the box structure, outside the furnace, toward the open end in the furnace, a fuel feeder-drum rotatably journaled across the box structure between the side walls over said grate adjacent to the closed end wall, said drum being of cam-like cross-section to provide a fuel receiving shoulder, a hopper for supplying fuel to the feeder-drum shoulder, a movable section pivoted on said box structure parallel to said drum for jolting action over said shoulder, and a fuel pusher disposed on and across the grate parallel to the drum.

GEORGE A. FERRELL. 

